January 31, 2012 – Linear Technology Korea (CEO Hong Sa-kwak) announced the release of an overvoltage protection controller for electronic systems (Product Name: LTC4366). Capable of operating from 9V to over 500V, the LTC4366 floating surge stopper utilizes an adjustable floating topology to enable operation even at very high voltages, regardless of the LTC4366's internal circuit voltage rating. Two internal shunt regulators combined with external voltage-dropping resistors create the LTC4366's internal supply rails. The maximum operating voltage is set by the breakdown of external resistors and MOSFETs. The LTC4366 is the first product of its kind to offer the capability to protect a 12V circuit from 500V transients without the need for additional protection components.
The LTC4366 monitors the voltage at the output and responds quickly to input supply overvoltage through gate control of the N-channel MOSFET. By regulating the output to a user-defined voltage during overvoltage transients, the LTC4366 allows the overvoltage across the MOSFET to drop while the load continues to operate. An adjustable fault timer enables safe shutdown if the fault persists.
The LTC4366 is ideal for demanding industrial, automotive, and aerospace applications where the system must continue to operate reliably even during extreme overvoltage events. High-voltage applications include motor overvoltage protection, coupled overvoltage, and failures of incorrect input supplies or power supplies. While conventional protection circuits relied on bulky inductors, capacitors, fuses, and transient suppressors to address overvoltage, the LTC4366 provides protection by regulating overvoltage. This product is available in ultra-small 8-pin TSOT-23 and 3mm x 2mm DFN packages. During operation, the entire circuit consumes only a small amount of power, such as a few milliamperes, and this product can be shut down at less than 20µA.
The LTC4366 is available in two options: the LTC4366-1, which latches off after a failure, and the LTC4366-2, which retries after a 9-second cooldown. These products operate over the full general commercial, industrial, and automotive temperature ranges. Pricing is $2.65 per unit for 1,000 units, and they are currently available for mass production. For more information, please visit www.linear.com/product/LTC4366 .

Photo caption: Floating surge stopper protecting devices from 800V surge voltage

Product Features: LTC4366


• Robust floating topology with user-adjustable maximum output
• Wide operating input and output voltage range: 9V ~ 500V
• Output clamp voltage is adjustable
• Set maximum input voltage using an external N-channel MOSFET
• Adjustable protection timer
• Built-in 9-second cooldown timer
• Shutdown current less than 20μA
• 8-pin TSOT and 3mm x 2mm DFN packages